Yeast biota of naturally fermented black olives in different brines made from cv. Gemlik grown in various districts of the Cukurova region of Turkey.

In this study, the yeast microbiota of naturally fermented black olives made from cv. Gemlik, grown in three different districts of the Çukurova region of Turkey, were investigated. Fermentations were conducted for 180 days in three different brines, including NaCl 10% w/v, NaCl 8% w/v and NaCl 8% w/v added with glucose 0.5%. In total, 223 yeasts were isolated and then identified by PCR-RFLP analysis of the 5.8S ITS rRNA region and sequence information for the D1/D2 domains of the 26S rRNA gene. A broad range of yeast biodiversity was identified, including eight genera and nine species. Candida boidinii (41%), Wickerhamomyces anomalus (32%) and Saccharomyces sp. (18%) were predominant yeasts throughout the fermentations. To a lesser extent, the other species, Candida aaseri, Meyerozyma sp., Zygoascus hellenicus, Pichia kudriavzevii, Schwanniomyces etchellsii and Candida atlantica were also members of the olive-fermenting microbiota. In Tarsus and Bahçe districts C. boidinii and in Serinyol district Saccharomyces sp. were the most frequently identified species. W. anomalus was the most frequently isolated species (by 48% of total yeasts) in NaCl 10% brines. C. boidinii was the most dominant species in the brines, including NaCl 8% and NaCl 8% + glucose 0.5%, with frequencies of 42% and 61%, respectively. At the end of the 180 days of fermentation, total acidity values of the brines were in the range 1.04-8.1 g/l lactic acid. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of Growing Regions on Discrimination of Turkish-Style Black Table Olives from Gemlik Cultivar.

Gemlik is a cultivar that grows in a distinct region of Turkiye and is ideal for brine fermentation of brine black table olives. Bursa Protected Designated Origin (PDO) and Izmir non-PDO Gemlik table olives have high levels of oleic acid (74%), total phenol (190 mg/kg), and dry matter (57%), while being low in linoleic acid (8%). The pH values and salt contents were observed to be in the range of 4.1 to 4.3 and 3.9% to 4.8%, respectively. During the fermentation of Gemlik table olives, a mass transfer occurred, resulting in a reduction in reducing sugar and total sugar contents as well as an increase in the salt content of the olives. Despite the reduction of phenolic content in both Gemlik PDO and non-PDO table olives, their antioxidant capacity remains high after fermentation. The oil content, antioxidant activity, phenolic contents, palmitic, palmitoleic, oleic, and linoleic acids were all found to be significant variables in distinguishing between Gemlik PDO and non-PDO table olives using PLS-DA analysis. There is a statistically significant correlation between the phenolic content and oleic (0.588) and linoleic (-0.659) acids (p < 0.05). Bursa PDO and Izmir non-PDO exhibit enhanced nutritional quality and antioxidant activity, unequivocally differentiating them from Hatay and Mersin non-PDO Gemlik table olives with 98% accuracy through discriminant analysis (p < 0.05). PLS-DA and DA can effectively identify variations in the quality of Turkish-style black table olives preserved in brine, originating from PDO and non-PDO growing areas.

Assessment of phytoplankton and environmental variables for water quality and trophic state classification in the Gemlik Gulf, Marmara Sea (Turkey).

Phytoplankton assemblages related to environmental factors and ecological status of the Gemlik Gulf were investigated between June 2010 and May 2011. A total 155 phytoplankton species were detected and 6 taxa (Amphisolenia laticincta, Archaeperidinium minutum, Cochlodinium sp., Gynogonadinium aequatoriale, Heterocapsa rotundata and Metaphalacroma sp.) were new records for the Turkish Seas. The lowest and highest total phytoplankton abundance among the sampling units (depths) was recorded in April 2011 (7.4×103cellsL-1) and July 2010 (251.8×103cellsL-1). Local small patches of visible red tide events were detected especially in the gulf, although a phytoplankton bloom was not observed. The water column was well stratified in the early autumn and well mixed in the early spring according to stratification index values. Surface nutrient concentrations increased especially at stations located inside of the gulf. The limiting effect of silicate was observed in early, mid-summer and early winter periods while the nitrogen was the limiting nutrient in the gulf during the whole sampling period. In the Gulf, low water quality-high mesotrophic and bad water quality-eutrophic status, high quality and low trophic level were generally detected according to Chl a, dissolved oxygen and trophic index. However, indices developed to determine the trophic level and water quality of the Mediterranean Sea can give unexpected results about the current environmental quality status when it is applied to the Marmara Sea which has limited photic zone by the halocline-pycnocline and thermocline.